gh-130567: Remove optimistic allocation in locale.strxfrm() #137143
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On modern systems, the result of wcsxfrm() is much larger the size of the input string (from 4+2*n on Windows to 4+5*n on Linux for simple ASCII strings), so optimistic allocation of the buffer of the same size never works.
Modules/_localemodule.c
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picnixz
changed the title
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If this is a bug fix, it needs a NEWS entry. If the bug will be fixed in other way -- it is just cleanup and minor optimization not worth a NEWS entry. |
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Actually, optimistic allocation works if the locale was not set or set to "C". But why would you use |
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This PR should fix a crash discussed in #130567 (comment). So this is a bug fix. If we are not going to backport it, we need another PR to fix it. |
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Let's backport it [edit: to 3.14.1], even if can't reproduce the corruption on my system. |
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Created a simpler PR #138940 for the fix. |
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Do you want to update this one? |
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On modern systems, the result of wcsxfrm() is much larger the size of the input string (from 4+2n on Windows to 4+5n on Linux for simple ASCII strings), so optimistic allocation of the buffer of the same size never works.